This invention relates to a vehicle vicinity-monitoring apparatus for monitoring the vicinity of a vehicle.
As means for securing visibility at the front side of a vehicle in a dark condition as during the driving at night, there is known a technique in which a night-vision camera, having an infrared camera, is installed on a front portion of a vehicle so as to secure the visibility by a night-vision image obtained by it. On the other hand, as means for eliminating left and right blind angle regions of the vehicle, there is known a technique in which a monitoring camera for monitoring the left and right blind angle regions of the vehicle is installed on the front portion of the vehicle so as to eliminate the left and right blind angle regions of the vehicle by a monitoring image obtained by it.
Usually, an image pickup device, such as a CCD, is used in a monitoring camera, and such an image pickup device has a certain degree of sensitivity even to the infrared region which can not be perceived by a man, and therefore an image of a scene, picked up by it, is different from the scene which the man actually views. Therefore, in the monitoring camera, an image of the scene is picked up through an infrared absorption filter which intercepts the infrared region so that the picked-up image can be made close to the scene which the man actually views. On the other hand, a night-vision camera utilizes infrared, and therefore is used without an infrared absorption filter.
As described above, the monitoring camera and the night-vision camera are different in constituent devices from each other, and therefore in the case of providing the vehicle with both of a night-vision function and a blind angle-monitoring function, it has heretofore been necessary to install both of a camera, exclusively designed for night-vision purposes, and a camera, exclusively designed for blind angle-monitoring purposes, on a front portion of the vehicle.
However, when the camera for night-vision purposes and the camera for the blind angle-monitoring purposes are both installed on the vehicle, there is a disadvantage that the cost is high.
And besides, in some districts, the night-vision function is not so frequently used, and there is a disadvantage that the installation of the night-vision camera makes customers in such districts feel that it is rather expensive, and this would lower the customers"" will to purchase the vehicle.
It is therefore an object of this invention to provide a vehicle vicinity-monitoring apparatus capable of performing both of a blind angle-monitoring function and a night-vision function with a single camera (that is, a single image pickup device).
The above problems have been solved by a vehicle vicinity-monitoring apparatus of the invention of aspect 1 which comprises a casing having a vicinity-monitoring window portion and a night-vision window portion; a single image pickup device which is contained within the casing, and has an image pickup surface which is divided into a vicinity-monitoring image pickup region and a night-vision image pickup region; an optical system which is contained within the casing so as to cause incident light, passing through the vicinity-monitoring window portion, to be focused on the vicinity-monitoring image pickup region of the image pickup device, and also causes incident light, passing through the night-vision window portion, to be focused on the night-vision image pickup region of the image pickup device; and an infrared absorption filter provided on an optical path of travel of the incident light which passes through the vicinity-monitoring window portion in the casing, and is focused on the vicinity-monitoring image pickup region of the image pickup device through the optical system.
In the invention of aspect 2, the infrared absorption filter is mounted on the optical system.
In the invention of aspect 3, the infrared absorption filter is mounted at the vicinity-monitoring window portion in the casing.